Fertility of degraded chernozem in short grain-beet crop rotations

Abstract

The purpose. To study influence of structure of crop rotation upon agrochemical and physicochemical parameters of fertility of degraded chernozem at application of organic-and-mineral fertilizer system and long-term growing of crops. Methods. Long-term field and analytical. Results. Changes of nutritive regime and physical and chemical properties of degraded chernozem are shown at different saturation of crop rotation by perennial grasses, row crops, grain and leguminous crops. Conclusions. On completion of two rotations the highest content of humus in degraded chernozem on the background of dung in dose of 7,5 t/hectare + N45P45K35 for 1 hectare of crop rotation area is determined in crop rotations of the following structures: 1) a share of cultivated crops in crop rotation — up to 25%, perennial grasses — up to 25, grain — more than 50%; 2) a share of leguminous cultures — 25%, grain — 50, row crops — 25 %. Increase of a share of cultivated crops in crop rotation up to 50% aggravated physical and chemical soil characteristics: pH salt dropped to 5,6 – 5,7, Ng — increased up to 2,2 – 2,5 mg-eq./100 g, S — dropped to 22,0 – 23,6 mg-eq./100 g of soil. Saturation of crop rotation by row and cereal crops had no essential influence on phosphatic and potash regimes of soil. The optimum content of mobile phosphorus and potassium in degraded chernozem was observed at use in crop rotation of buckwheat and pease.